The European Food Safety Authority (EFSA) has concluded that the information in a scientific paper on the possible effect of diacetyl in enhancing β-amyloid-induced neurotoxicity "does not bring any new scientific elements" in the assessment for the safe use of diacetyl in food.

The EFSA was asked by the European Commission to assess a paper called “The Butter Flavourant, Diacetyl, Exacerbates β-amyloid Cytotoxicity” published in ACS' journalChemical Research in Toxicology in 2012, on the possible effect of diacetyl in enhancing β-amyloid-induced neurotoxicity, and to verify whether these additional data are of concern for the safe use of diacetyl as a flavoring substance in food.

In the scientific paper, the authors conclude that industry workers exposed chronically via inhalation to diacetyl could possibly develop neurological symptoms related to diacetyl exposure, such as intensifying the damaging effects of an abnormal brain protein linked to Alzheimer's disease. EFSA evaluated the paper in relation to the potential risk of the use of diacetyl as flavoring agent in food and its evaluation concluded that the cytotoxicity assay and the cellular system used by the authors have shortcomings that did not allow the extrapolation of the data to be used in the safe assessment of diacetyl as a flavoring agent in food.

"Additionally, the authors have not provided any correlation between occupational exposure and systemic exposure," the EFSA said.